The present invention relates to a cordless telephony device comprising a module called base and at least a module called handset, in which each module includes a transmitting and a receiving circuit comprising, inter alia, means for settling on a channel of a plurality of channels which have different frequencies, an element called scanning element for receiving and analyzing the various channels in turns so as to examine whether a request for a connection is sent out on a channel by another module, and means for incorporating in the data of a data transmission on a given channel a data that defines the channel used.
A radio telephone as defined in the opening paragraph above is known from the document EP-A-0 055 097. According to this document, a cellular telephone receives data indicating, for example, the channel number used by the transmitter.
In a cordless telephony device, a parasitic modulation is likely to occur during a scanning phase, if one entity, base or handset, transmits a carrier on a given channel, which modulation results in the fact that the receiver in the scanning mode may then receive this carrier although the receiver has settled on another channel. This receiver may thus be led to an error and be put in the receive mode on an unsuitable channel. To avoid this, there is habitually provided that the receiver reads the number indicated in the data, verifies the correspondence thereof with the channel on which it is settled and, if there is no correspondence, discards the reception and continues the scanning operation.
It is an object of the invention to render the response to a request for a connection between the base and the handset faster.
For this purpose, each module comprises means for reading from the data of the analyzed channel during a scanning operation the data that corresponds to the channel number and for immediately settling on the channel that carries this number if this channel number is different from that of the analyzed channel.
The invention is thus based on the idea of utilizing data, possibly received by error, for deriving useful information therefrom.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.